Sulphurized oils



Patented Sept. 22, 1931 UNITED STATES PATENT OFFICE ELMER W. ADAMS, OFHAMMOND, INDIANA, ASSIGNOR TO STANDARD OIL COMPANY, 01 WHITING, INDIANA,A CORPORATION OF INDIANA 3 SULPHURIZED OILS The present inventionrelates to improvements in sulphurized oils, such oilsbeing useful forthe lubrication of cutting tools and the like.

The present invention has to do more particularly with sulphurizedcutting oils consistin principally of hydrocarbon oils and free romfatty oils. In the production of such oils in the past, employing highgrade lubricating oil fractions, such as lubricant distillates fromMid-Continent and Pennsylvania crudes as a base, it has been possible tosecure a product containing only up to about 3% total sulfur, and suchoils, when so prepared as to contain above 2% of total sulfur, areextremely dark, being almost black. As a result their use makes itsubstantially impossible to follow closely the Work of a cutting tool.Furthermore, by producing the oils in the manner hitherto employed, if alight colored cutting oil is desired, free from animal or fatty oils, itmust be pre ared of so low a sulfur content as to markedly reduce itsvalue as a cutting lubricant.

Although the value of the oil as a cutting lubricant has hitherto beenattributed to the additional sulfur incorporated into the oil by heatingelemental sulfur therewith, it has now been found that by incorporatingsulfur into a hydrocarbon stock having initially a high sulfur content,say in excess of 0.75%, an additional quantity of sulfur can beincorporated so that sulphurized cut-. ting oils containingsubstantially in excess of 3% total sulfur can be secured, andrelatively light colored products containing as high as 2 to 3% sulfurcan be prepared. It has furthermore been found that, on incorporation ofadditional elemental sulfur into such stocks having initially highsulfur content, thetotal sulfur is of effective value in cuttinglubrication. v

The optimum condition for incorporatmg sulfur into such mineral oils,has been found to be the heating of a slight excess of sulfur with thedesired lubricating oil fraction at temperatures 300'to 350 F. for aperiod of 3 to 5 hours. For example, by heating a coastal distillate oilof 200 sec. viscosity at Application filed August a, 1929. Serialm'aauos.

100 F. and 2.5% sulfur content with sulfur in the proportion of 100gallons of oil to 39 lbs.- of sulfur to 350 to 360 F. for 5 hours withagitation by steam, and straining out the sludge and unused sulfur, aproduct fur content is desired, a treated high-sulfur lubricant fractionmay be employed."

Such products, derived, for example, y the ordinary sulfuricacidtreatment and clay filtration of high sulfur lubricant fractions,may contain from .75% sulfur u and products containing as high as 2.5 to3 a sulfur and having a color of 3 to. 6 N. P. A. can be secured. Thusby heating a refined hydrocarbon distillate having a viscosity of 110sec. at 100 F. and a sulfur content of 1.3% with 2% of sulfur at a.temperature of 300 to 320 F. for 3 hours, a product haVing a 2.8% sulfurand a color of 44 N. A. is secured. A product of similar sulfur content,produced by the methods and from the stocks hitherto employed, would bepractically black, and would have no better value as a cutting lubricantthat the relatively light product pro? duced in accordance with thepresent invention.. It appears that, after the incorporation of theadditional sulfur, the ori 'nal sulfur as well as the additional sulfurunction to improve the value of the oil as a cutting lubricant.

I claim:

1. The method of producing a sulphurized cutting oil which comprisesincorporatin into hydrocarbon oil free from fatt oil and containinginitially at least 0.75 0 sulfur, additional sulfur suflicient to bringthe total sulfur content of the oil to at least 2%.

2. The method of producing a light colored sulphurized cutting oil whichcomprises heat- A similar treatment of a disti ate ing a treatedhydrocarbon oil distillate free 3%, said heating being at a temperatureof 300 to 350 F.

3. The method of producing a sulphurized cutting oil which comprisesheating a hydro- 5 carbon oil distillate free from fatty oil andcontainin at least 0.75% sulfur, with additional sul ur to bring thetotal sulfurccontent of the oil to at least 2%, the heating being at atemperature of 300 to 350 F.

4. A sulphurized cutting oil consisting principally of hydrocarbon oilhaving an initial sulfur content of at least 0.75% and free from fattyoil, said cutting oil containing 2-3% sulfur and having a color ndtdarker than 6 N. P. A.

5. The method of producing a sul hurized cutting oil having a color notdar er than 6 N. P. A. and having a total sulfur content of at least 2%which comprises incorporatgo ing into hydrocarbon oil free from fatt oiland containing initially at least 0.75% su fur,

additional sulfur suflicient to bring the total sulfur content of theoil to at least 2%.

6. The methodof producing a sulphurized 5 cutting oil having a color notdarker than 6 N. P. A. and having a total sulfur content as high as 3%which comprises heating a treated hydrocarbon oil distillate free fromfatty oil and containing initially at least 0.7 5% sulfur, withadditional sulfur sufiicient to bring the total sulfur content 11 to thede-* sired proportion, said heating eing at a temperature of 300 to 350F.

. 7 A sulphurized cutting oil consisting principally of hydrocarbon oilhaving an initial sulfur content of at least 0.7 5% and containing from1.25% to 2.25% of added sulfur,

aid cutting oil being free from fatty oil and liavin a color not darkerthan 6 N. P. A.

8. v sulphurized cutting oil containing hydrocarbon mineral oilhaving atotal sulfur content in excess of 3% of the hydrocarbon oil andincluding at least 0.75% initial sulfur content of the hydrocarbon oiland the remaining sulfur combined directly with the hydrocarbon oil.

ELMER W. ADAMS.

